unexpected-immutable

This plugin lets you compare Immutable data structures, and makes the diff as pretty as all the others are.

API

Data types

Immutable is the general Iterable data type, serving as a base for the others.

ImmutableKeyed represents 'object-like' Immutable types, such as Map.

ImmutableIndexed covers 'array-like' types, such as List.

Assertions

This library provides to satisfy assertions for the above data types. It ensures that they can be compared against each other as well as against comparable JavaScript objects (i.e. {} or []).

Indexed types also have most of the assertions of unexpecteds array-like data type (in particular to have items satisfying), while keyed types will have most of the object-like assertions.

New assertions

The to have value at <path> assertion follows the given path (given either as an array of identifier strings, or as a period- or slash-separated string) to verify its presence. Another argument may be added to provide a value to check equality against. Examples:

// Checks that there is a key at this location
expect(collection, 'to have value at', ['start', 'user', 'ident']);
// Checks same location, verifies that value is 'myUser'
expect(collection, 'to have value at', 'start/user/ident', 'myUser');

The value at <path> intermediate assertion will attempt to follow the given path into an Immutable collection, allowing further assertions on the value. If it does not exist, the assertion fails. Examples:

expect(collection, 'value at', ['start', 'user', 'ident'], 'to be ok');
expect(collection, 'value at', 'start/user/ident', 'to match', /User$/);
expect(collection, 'value at', 'start.user', 'to satisfy', { ident: 'myUser' });